TITLE:
Study and Redesign of Aircooler System in a 16 MW Steam Turbine Surface Condenser at Neka Power Plant
AUTHORS:
Edris Ghonoodi, Mofid Gorji Bandpy
KEYWORDS:
Aircooler, CFD, Condenser, Ducts, Tube Rupture, Exhaust Pressure, Exhaust Temperature, Mixture Flow
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.9 No.7,
July
29,
2021
ABSTRACT: According to the study
of basic Rankin thermal cycle, the steam exhaust
pressure of a typical steam turbine toward the condenser, plays a great role in the efficiency and the net output power of the steam turbine, so most
surface condensers that are working in thermal power plants are kept at vacuum condition so that the maximum power of thermal cycle can be
achieved. The vacuum pressure at condenser leads to the entering of air and Non-condensable gases from turbine gland seals to
condenser so that the special air ejection equipment is being used to take
apart air from steam and vent it to out of condenser. In this study, a special steam and air separator mechanism in an evacuating system called “Aircooler” at a 16 MW steam turbine condenser
is being studied and the Fluent CFD software is utilized to analyze the
behavior of steam plus air in a typical aircooler system of 16 MW steam turbine condenser
of Neka power plant to find a way to reduce the risk of cooling tube rupture in
aircooler ducts. The critical condition which tube rupture happens is determined
and it is demonstrated that in hot seasons of year, by increasing the seawater
cooling temperature and increasing in turbine steam exhaust pressure and
temperature, the risk of tube rupture due to more mixture velocity at the first
row of aircooler cooling tubes increases and also the effect of tube plugged condition on the performance of aircooler
shows that the risk of other tubes rupture will increase and thus the
efficiency of aircooler decreases due to more aircooler exhaust temperature.
Finally, two
modified plans at aircooler system design will be studied and simulated via
Fluent CFD software which leads to reduce the risk of tube rupture. The results
show that by modification of aircooler ducts and holes, the mixture air and
steam flow velocity to first aircooler cooling tube row decreases significantly
and causes the risk of tube rupture to decrease remarkably and also the exhaust temperature
of aircooler decreases and causes the higher ejector performance.